Numerical study of electrical behavior of P3HT/PCBM bulk heterojunction solar cell

In this work the program AMPS-1D was used to optimize the performance of the organic solar cells. The cells considered consist of poly(3-HexylThiophène) [P3HT] as electron donors, and (6,6)-phenyl- C61-butyric acid methyl ester [PCBM] as electron acceptor, (P3HT/PCBM) is used as photo-active material, sandwiched between a transparent indium tin oxide (ITO) and layer of poly(3,4 ethylenedioxythiophene)/ poly(styrenesulfonate) (PEDOT/PSS) on top of the ITO electrode and an AL backside contact. The results showed that the optimum thickness of the solar cell is about 400 nm, V_oc = 0.61 at T = 300 K. This is in the good agreement with the corresponding computer simulation value of 0.63 V. The maximum limit for the organic solar cell efficiency is about 8%, provided that the band-gap of the cell is about 1.5 eV.     

Head pose estimation based on face symmetry analysis

This paper addresses the problem of head pose estimation in order to infer non-intrusive feedback from users about gaze attention. The proposed approach exploits the bilateral symmetry of the face. Size and orientation of the symmetrical area of the face is used to estimate roll and yaw poses by the mean of decision tree model. The approach does not need the location of interest points on face and presents robustness to partial occlusions. Tests were performed on different datasets (FacePix, CMU PIE, Boston University) and our approach coped with variability in illumination and expressions. Results demonstrate that the changes in the size of the regions that contain a bilateral symmetry provide accurate pose estimation.     

Influence of growth time on crystalline structure, conductivity and optical properties of ZnO thin films

This paper examines the growth of ZnO thin films on glass substrate at 350 ℃ using an ultrasonic spray technique. We have investigated the influence of growth time ranging from 1 to 4 min on structural, optical and electrical properties of ZnO thin films. The as-grown films exhibit a hexagonal structure wurtzite and are (002) oriented. The maximum value of grain size G = 63.99 nm is attained for ZnO films grown at 2 min. The average transmittance is about 80%, thus the films are transparent in the visible region. The optical gap energy is found to increase from 3.26 to 3.37 eV with growth time increased from 1 to 2 min. The minimum value of electrical resistivity of the films is 0.13 Ω·cm obtained at 2 min. A systematic study on the influence of growth time on the properties of ZnO thin films deposited by ultrasonic spray at 350 ℃ has been reported.     

Effect of substrate temperature on the stability of transparent conducting cobalt doped ZnO thin films

Transparent conducting Co doped ZnO thin films have been fabricated by Ultrasonic spray. The thin films were deposited at three different substrate temperatures of 300, 350 and 400 ℃. The obtained films had a hexagonal wurtzite structure with a strong (002) preferred orientation. The maximum crystallite size value of the film deposited at 350 ℃ is 55.46 nm. Spectrophotometer (UV-vis) of a Co doped ZnO film deposited at 350 ℃ shows an average transmittance of about 90%. The band gap energy increased from 3.351 to 3.362 eV when the substrate temperature increased from 300 to 350 ℃. The electrical conductivity of the films deposited at 300, 350 and 400 ℃ were 7.424, 7.547 and 6.743 (Ω·cm)^-1 respectively. The maximum activation energy value of the films at 350 ℃ was 1.28 eV, indicating that the films exhibit a n-type semiconducting nature.     

Sulfuric Containing Sugar Bath and Permanent Weak Magnetic Field Effect during Anodizing AlCu<Subscript>6</Subscript>Si Alloy Sheet Surfaces

Rolling and perpendicular to rolling surfaces of AlCu₆Si aluminum sheet have been anodized at 27 ± 1°C in 20 wt % sulfuric acid containing an additive of white sugar powder with and without permanent weak magnetic field. After one hour of anodizing, some hillocks-shaped micropores are developed and craters are formed in the oxide layers. The micropores obtained in rolling faces are often smaller than those obtained on other faces. Sulfuric anodizing at 21 V causes the formation of combined micropore-nanopore structures in rolling surface. It demonstrated that sugar additive increases the density of micropores in spherical shape in rolling surface and the increasing of sugar concentration changes the pores to hillocks form. In addition, the application of weak magnetic field induces homogeneous repartition of micropores.     

Application of a boundary integral method to the optimization ofsolid rotor machines

This paper is devoted to the optimization of electric machine solid rotors for high speed applications, using a boundary integral method. The method is applied to two examples: a slotted asynchronous rotor; and a salient reluctant synchronous rotor. Starting under constant voltage is especially studied in both cases. An important part of the paper deals with the asynchronous motor. An idealized stator generates a sinusoidally distributed tangential flux density, so that the optimization concerns only the rotor slotting. At constant permeability, the boundary integral method proves to be very fast and efficient for the approximate design of a slotted rotor     

Management of Multimedia Scenarios in an Object-Oriented Database System

In this paper, we present an approach to multimedia scenario management in a database system that considers : object-oriented concepts for multimedia and scenario modeling; both known and unknown multimedia object playing duration; temporal specification language; Petri net automatic generation based on temporal specifications; automatic detection of user temporal specification errors and contradictions; and finally user interactions based on composite Petri net features.